Spool for reeling and unreeling strip material



1965 o. WINKEL 3,201,059

SPOOL FOR FEELING AND UNREELING STRIP MATERIAL Filed Jan. 22, 1963 INVENTOR 0770 W/A A EZ United States Patent Filed Jan. 22, 1963, Ser. No. 253,117 7 Claims. (Cl. 24274.1)

This invention concerns a spool for reeling and unreeling strip material, and more particularly means for attaching an end portion of such strip material to the core of the spool. The strip material in question may be a photographic film, a magnetic recording tape, certain types of typewriter ribbon or strip and the like.

Various types of spools for reeling and unreeling strip material of the above mentioned types are known which include means for attaching one end of the strip material to the core of the spool. However, it has been found that these known types of spools are unsatisfactory in various respects. In some cases the means of attachment cause the actual core portion to deviate quite substantially from a cylindrical form with the result that in the individual turns of the wound strip material the radius of curvature changes substantially and irregularly in certain places which is undesirable. In other cases, the means of attachment are rather involved in structure and therefore comparatively expensive in manufacture. In still other cases the attachment of the end portion of the strip material does not take place automatically but requires additional manipulation by the operator. in many cases only a slot is provided in the core of the spool into which the strip isto be inserted. However, such insertion of the strip into a slot does not provide a reliable attachment and very frequently the strip end slips out of the slot against the wishes of the operator. In most cases only one or only a few points of attachment are providedon the core so that when the strip material is to be attached to the spool first a suitable position of the spool must be provided for in order to find access to the particular point of attachment. 1

It is therefore one object of this invention to provide for a spool which is very simple in structure and there fore comparatively inexpensive in manufacture and which is capable of automatically clamping the end portion of the stripmaterial when the latter is placed in proper position relativeto the spool. l i

It is another object of this invention to provide for a spool of the type set forth in which a great number of points of attachment is provided so that the end of the strip material can be attached practically in any position of the spool.

With above objects in mind the invention includes a spool for reeling and unreeling strip material, comprising, in combination, core means having a substantially cylindrical center portion and having flanges spaced from each other in axial direction a distance at least equal to the-width of the strip material, said center portion havrotary motion of said hollow cylindrical body relative to said core means takes place, said end portion of the strip material is automatically clamped between one of said edges of said recess, on one hand, and. said hollow cylindrical body at one edge of said slot thereof, on the other hand. i

It will be seen that the spool according to. the invention entails the remarkable advantage that the strip material introduced into the spool is automatically clamped therein without any manipulation of clamping members or the like, because the spool essentially consists of two members rotatable one relative to the other so core of the spool, the remaining Finally that the clamping action takes place as soon as one of these two parts is rotarily moved relative to the other. This action may take place already by pulling onthe introduced film or strip material in a direction which is tangential or at least not radial to the spool members.

The novel featureswhich are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantagesthereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIG. 1 is a perspective illustration of a portion of the portions of the spool being shown in phantom only lines; 3

FIG. 2 is a perspective illustration of a modification of the core structure according to the invention;

FIG. 3 is a perspective view of two portions of the spool according to the invention showing in what manner strip of material is inserted forjattachment;

FIG. 4 is a partly cross-sectional elevation of an assembled spool according to the invention; and

FIG. 5 is an exploded perspective view illustrating a further modification of the invention.

As can be seen from FIG. 1, in one embodiment of the inventionthe center portion 1 of the core is a solid starshaped body mounted between and attached to the conventional flange plates 2 and 2'. The body 1 may be considered to be a substantially cylindrical body rovided with a plurality of recesses extending in axial direction of the core and defined each on two sides by the edges of the adjacent tooth-shaped projections of "the star-shaped body 1. i

FIG. 2 illustrates a modification according to which i the center portion of the core is not a solid body 1 as in flange plates 2 and 2 so as to constitute ing at its perimeter at least one recess defined on two N sides by edges which extend in axial direction of said center portion and having a predetermined depth in radial direction; and clamping means formed as a freely rotatable hollow cylindrical body coaxially surrounding said center portion of said core means and having at least one slot extending in said axial direction for permitting, when said. slot is substantially in radial alignment with said recess of said center portion, insertion of an end portion of the strip material through said slot into said recess, the difference between the radial distance of atleast one of said edges of said recess from the axis of said center portion, on one hand, and the radial distance of the inner surface of said hollow cylindrical body at said slot from said am's, on the other hand, being so small that, when after said insertion of said end portion of the strip material a FIG. 1 but is constituted by a plurality'of prismatic bar members 3 which may be attached by welding, riveting, cementing or any other suitable means between the two the equivalent of the star-shaped body 1. r i I p FIG. 3 illustrates the structure of the spool according to the invention withoutthe flange plates 2 and 2. illustrated the star-shaped body 1 is surrounded co-axially by a freely rotatable hollow cylindrical member 4 which is provided with a plurality of axially extending slots 5. Preferably the number of the slots 5 is equal or at least equal to the numberof the recesses betweenthe individual projections of the star-shaped body 1. As can be seen,

. when any one of the slots 5 is substantially in alignment with one of the recesses of the body 1 a strip dean be inserted with its end portion through the particular slot 5 and into the corresponding recess of the body 1. If now the spool i.e. the center portion 1 is started to rotate by conventional drive means in either one direction While the end of the strip 6 is held stationary and consequently also the hollow cylindrical member l, one of the edges adjacent to the recess into which the forward end of the strip 6 has been inserted will immediately and automatically grip the free end of the strip 6 and clamp it relative to the member 4,

On the other hand, if the spool and the member 1 are standing still a slight movement of the end of the strips 6 will cause the freely rotatable member 4 to follow with the result that also in this case the end of the strip 6 is clamped in the same manner as just described.

It will be understood that it is of great advantage to provide the member l with a substantial number of recesses and accordingly also the rotatable hollow member 4 with a substantial or corresponding number of slots 5 be cause under these circumstances the strip 6 can be inserted readily no matter in which position the spool happens to be. Nevertheless, it will be understood also that the advantageous eifect of the invention is also obtainable if the center portion of the core were a cylindrical body having only one recess and if the rotatable hollow member 4 would have only one slot.

Referring to FIG. 4 it will be understood that ordinarily the flange plates 2 and 2' of the spool should be spaced from each other a distance in axial direction which is at least equal to the width of the strip 6. Except in the case of FIG. 2 the central portion or body 1 will always be rigidly attached in conventional manner to the flange plates 2 and 2'. advantageous to provide the rotatable hollow cylindrical member 4 also with flanges 7 as shown in FIG. 4. In this case it is of course desirable to space these two flanges 7 from each other a distance substantially equal to the width of the strip 6. In addition, as shown in FIG. 4, it will be advisable in this case to provide the flange plates 2 and 2 on their inner faces with recesses 8 for accommodating the flanges 7 of the member 4.

In all the cases described above it must be borne in mind that the inner surface of the hollow cylindrical member 4 should fit closely over the outer edges of the projections of the center portion of the core. In other Words, the difference between the radial distance of at least one of the outer edges of the recesses from the axis of the spool, on one hand, and the radial distance of the inner surface of the hollow cylindrical body at the slot or slots thereof from said axis, on the other band, should be so small that, when after the insertion of the end portion of the strip material into one of the recesses a rotary motion of the hollow cylindrical body 4 relative to the core takes place, the end of thestrip material is automatically clamped between one of said edges of the respective recess, on one hand, and the hollow cylindrical body at one edge of its slot, on the other hand. Best effect is obtained if this radial difference is not greater than the thickness of the strip material.

FIG. 5 illustrates a modification of an arrangement according to the invention in which all the members of the spool are produced by injection molding from synthetic resin. In this case the center portion 1 of the core can be produced as one integral piece together with one of the flanges 2', while the other flange plate 2 is produced separately. The rotatable hollow cylindrical member 4 with its slots 5 is also produced separately in the same manner. After the member 4 is arranged in place surrounding the center portion 1 the second flange plate 2 can be attached in a simple manner e.g. by being provided with a' projecting portion 8 which fits into the opening of the center portion 1 for being connected therewith by cementing or by other suitable means.

The axial length of the slots 5 can be chosen arbitrarily. The length of the slots may be substantially equal or at least equal to the width of the strip materials 6. However, in special cases e.g. in the case of spools for receiving photographic films, the slots 5 may be slightly narrower than the film width as is indicated in FIG. 5, or these slots may even be tapered toward the axis of the spool because usually the free ends of photographic films are cut so ,as to have a triangular point and in this case only this pointed portion ofthe film needs be inserted into a slot 5 of the member 4 so as to be gripped by the re- In certain cases it may be spective edge of the center portion 1 or of the members 3 according to FIG. 2 in order to be clamped.

It will be understood that by making the length of the slots 5 somewhat smaller than the width of the strip material. the axial length of the entire spool can be reduce to a minimum.

Finally, it is to be noted that when a strip 6 is unreeled from a spool according to the invention, at the end of the unreeling operation the inner end of the strip need not be released by a manual operation from the core of the spool. The strip 6 will be released automatically on account of the free rotatability of the member d whereby the previous clamping action is automatically terminated.

7 above.

While the invention has been illustrated and described as embodied in a spool for reeling and unreeling strip material and comprising two portions rotatable one relative to the other, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis the foregoin. 'will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

Vv'hat is claimed and desired to be secured by Letters Patent is:

1. A spool for reeling and unreel-ing strip material, comprising, in combination, core means having a substantially cylindrical center portion and having flanges spaced from each other in axial direction a distance at least equal to the width of the strip material, said center portion having at its perimeter at least one recess defined on two sides by edges which extend in axial direction of said center portion and having a predetermined depth in radial direction said recess being symmetrical with respect to an axial plane passing through the axis of said core means and the deepest portion of said recess; and clamping means formed as a freely rotatable hollow cylindrical body :coaxially surrounding said center portion of said core means and having at least one slot extending in said axial direction said slot having edge portions of symmetrical configuration and permitting, when said slot is substantially in radial alignment with said recess of said center portion, insertion of an end portion of the strip material through said slot into said recess, the difference between the radial distance of at least one of said edges of said recess from the axis of said center portion,

on one hand, and the radial distance of the inner surface of said hollow cylindrical body at said slot from said axis, on the other hand, being so small that, when after said insertion of said end portion of the strip material a rotary motion of said hollow cylindrical body relative to said core means takes place in either clockwise or counterclockwise direction, said end portion of the strip material is automatically clamped between the corresponding edge of said recess, on one hand, and said hollow cylindrical body at the corresponding edge portion of said slot there of, on the other hand, thus firmly securing said strip material to said spool irrespective of the direction of rotation of said hollow cylindrical body relative to said core means.

2.. A spool for reeling and unreeling strip material, comprising, in combination, core means having a substantially cylindrical center portion and having flanges spaced from each other in axial direction a distance at least equal to the width of the strip material, said center portion having at its perimeter a plurality of circumferentially spaced recesses each defined on two sides by edges which extend in axial direction of said center portion and having a predetermined depth in radial direction each of said recesses being symmetrical with respect to an axial plane passing through the axis of said core means and the deepest portion of the respective recess; and

clamping means formed as a freely rotatable hollow cylindrical body coaxially surrounding :said center portion of said core means and having a plurality of circumferentially spaced slots extending in said axial direction, each of said slots having edge portions of symmetrical configuration permitting, when any one of said slots is substantially in radial alignment with one of said recesses of said center portion, insertion of an end portion of the strip material through said slot into said recess, the difference between the radial distance of at least one of said edges of said recesses from the axis of said center portion, on one hand, and the radial distance of the inner surface of said hollow cylindrical body at said slots from said axis, on the other hand, being so small that, when after said insertion of said end portion of the strip material a rotary motion of said hollow cylindrical body relative to said core means takes place in either a clockwise or a counterclockwise direction, said end portion of the strip material is automatically clamped between the corresponding one of said edges of said recess, on one hand, and said hollow cylindrical body at the corresponding edge portion of said slot thereof, on the other hand, thus firmly securing said strip material to said spool irrespectiveof the direction of rotation of said hollow cylindrical body relative to said core means.

3. A spool as claimed in claim 2, wherein said center connected with said flanges, the geometrical locus for the outer edges of said star-shaped body being an imaginary cylinder concentric with the axis of said core means.

4. A spool as claimed in claim 2, wherein said freely rotatable hollow cylindrical body is provided with flanges spaced from each other a distance substantially equal to the width of the strip material.

5. A spool as claimed in claim 4, wherein said flanges of said core means are provided at their inner faces with recesses for accommodating said flanges of saidhollow cylindrical body.

6. A spool as claimed inclaim 2, wherein said center portion of said core means is formed by a plurality of circumferentially spaced bar members connected between said flanges of said core means and defining between themselves said recesses, the geometrical locus for the outer edges of said bar members being an imaginary cylinder concentric with the axis of said core means.

7. A spool as claimed in claim 2, wherein said center portion of said core means is integrally formed with one of said flanges thereof, the other one of said flanges being a separate member assembled with sa id center portion.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 12/26 Germany.

4/39 Great Britain.

MERVIN STEIN, Primary Examiner. 

1. A SPOOL FOR REELING AND UNREELING STRIP MATERIAL, COMPRISING, IN COMBINATION, CORE MEANS HAVING A SUBSTANTIALLY CYLINDRICAL CENTER PORTION AD HAVING FLANGES SPACED FROM EACH OTHER IN AXIAL DIRECTION A DISTANCE AT LEAST EQUAL TO THE WIDTH OF THE STRIP MATERIAL, SAID CENTER PORTION HAVING AT ITS PERIMETER AT LEAST ONE RECESS DEFINED ON TWO SIDES BY EDGES WHICH EXTEND IN AXIAL DIRECTION OF SAID CENTER PORTION AND HAVING A PREDETERMINED DEPTH IN RADIAL DIRECTION SAID RECESS BEING SYMMETRICAL WITH RESPECT TO AN AXIAL PLANE PASSING THROUGH THE AXIS OF SAID CORE MEANS AND THE DEEPEST PORTING OF SAID RECESS; AND CLOAMPING MEANS FORMED AS A FREELY ROTATABLE HOLLOW CYLINDRICAL BODY COAXIALLY SURROUNDING SAID CENTER PORTION OF SAID CORE MEANS AND HAVING AT LEAST ONE SLOT EXTENDING IN SAID AXIAL DIRECTION SAID SLOT HAVING EDGE PORTIONS OF SYMMETRICAL CONFIGURATION AND PERMITTING, WHEN SAID SLOT IS SUBSTANTIALLY IN RADIAL ALIGNMENT WITH SAID RECESS OF SAID CENTER PORTION, INSERTION OF AN END PORTION OF THE STRIP MATERIAL THROUGH SAID SLOT INTO SAID RECESS, THE DIFFERENCE BETWEEN THE RADIAL DISTANCE OF AT LEAST ONE OF SAID EDGES OF SAID RECESS FROM THE AXIS OF SAID CENTER PORTION, ON ONE HAND, AND THE RADIAL DISTANCE OF THE INNER SURFACE OF SAID HOLLOW CYLINDRICAL BODY AT SAID SLOT FROM SAID AXIS, ON THE OTHER HAND, BEING SO SMALL THAT, WHEN AFTER SAID INSERTION OF SAID END PORTION OF THE STRIP MATERIAL A ROTARY MOTLIN OF SAID HOLLOW CYLINDRICAL BODY RELATIVE TO SAID CORE MEANS TAKES PLACE IN EITHER CLOCKWISE OR COUNTERCLOCKWISE DIRECTION, SAID END PORTION OF THE STRIP MATERIAL IS AUTOMATICALLY CLAMPED BETWEEN THE CORRESPONDING EDGE OF SAID RECESS, ON ONE HAND, AND SAID HOLLOW CYLINDRICAL BODY AT THE CORRESPONDING EDGE PORTION OF SAID SLOT THEREOF, ON THE OTHER HAND, THUS FIRMLY SECURING SAID STRIP MATERIAL TO SAID SPOOL IRRESPECTIVE OF THE DIRECTION OF ROTATION OF SAID HOLLOW CYLINDRICAL BODY RELATIVE TO SAID CORE MEANS. 